Product identifiers
How to fix a missing or incorrect GTIN in Google Merchant Center
Choose the manufacturer-assigned GTIN when one exists, or submit the correct brand, MPN, and identifier_exists combination.
Reviewed against Google Merchant Center documentation on August 25, 2026. Independent guide; not affiliated with or endorsed by Google.
What the diagnostic means
Google shows this issue when unique product identifier values are missing, invalid, or not recognized for a product that is expected to have them.
Common causes
- A manufacturer-assigned GTIN was omitted or copied incorrectly.
- A barcode contains letters, has an unsupported digit count, or fails its check digit.
- A merchant invented a GTIN instead of using the manufacturer-assigned value.
- A product without a GTIN is also missing its brand and MPN, or identifier_exists is set incorrectly.
- The parent product GTIN was reused for variants that have their own manufacturer identifiers.
Resolution checklist
Fix it step by step
- Confirm whether the product has a manufacturer-assigned barcode; do not guess a number.
- For an assigned GTIN, enter the exact 8-, 12-, 13-, or 14-digit value and verify its check digit.
- For a product with no assigned GTIN, provide brand and MPN when they exist.
- Set identifier_exists to false only when the product genuinely has no unique product identifiers.
- Use the correct identifier for each variant and resubmit the corrected product data.
Before you resubmit
- GTIN contains a valid 8, 12, 13, or 14-digit value after spaces and dashes are removed.
- The check digit is valid and the number came from the manufacturer, not an internal SKU.
- Products without GTINs use the correct brand, MPN, and identifier_exists values.
- Each variant uses its own assigned GTIN rather than the parent’s identifier.
Product with no manufacturer identifiers
Before
gtin: [blank] brand: [blank] identifier_exists: yes
After
gtin: [blank] brand: [blank] identifier_exists: no
Frequently asked questions
Is a SKU the same as a GTIN?
No. A SKU is a merchant’s internal product identifier. A GTIN is a standardized identifier assigned to a trade item, normally by the manufacturer.
Should I make up a GTIN when one is missing?
No. Google says not to guess or invent one. Confirm whether an identifier exists and submit the correct identifier fields for that product.
Which GTIN lengths are accepted?
Google’s specification recognizes 8-, 12-, 13-, and 14-digit GTIN formats. Spaces and dashes may be ignored during interpretation, but the underlying number and check digit must be correct.